S
M
T
W
T
F
S
30
71°
47°
31
70°
46°
1
72°
50°
2
72°
55°
3
71°
57°
4
79°
57°
5
80°
55°
6
79°
47°
7
76°
46°
8
71°
46°
9
72°
45°
10
69°
48°
11
69°
50°
12
68°
45°
13
72°
49°
14
75°
51°
15
74°
50°
16
67°
49°
17
68°
50°
18
70°
49°
19
73°
42°
20
68°
44°
21
70°
41°
22
71°
40°
23
65°
40°
24
64°
41°
25
64°
43°
26
63°
39°
27
63°
39°
28
62°
41°
29
60°
37°
30
61°
37°
1
61°
43°
2
67°
37°
3
65°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mount Sunapee
Mount Sunapee's September 2026 forecast shows daily high temperatures ranging from 60° to 80°, with overnight lows between 37° and 57°. The average high for September is 69° with an average low of 46°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Mount Sunapee. See also: October | November | December.
